Pegah Jamshidi
Wiki wiki ([http://en.wikipedia.org/wiki/File:En-us-wiki.ogg i''']/ˈwɪkiː/ [http://en.wikipedia.org/wiki/Wikipedia:Pronunciation_respelling_key ''WIK'''-ee'']) is a website which allows its users to add, modify, or delete its content via a web browser usually using a simplified markup language or a rich-text editor.123 Wikis are powered by wiki software. Most are created collaboratively. Wikis serve many different purposes, such as knowledge management and notetaking. Wikis can be community websites and intranets, for example. Some permit control over different functions (levels of access). For example, editing rights may permit changing, adding or removing material. Others may permit access without enforcing access control. Other rules may also be imposed to organize content. Ward Cunningham, the developer of the first wiki software, WikiWikiWeb, originally described it as "the simplest online database that could possibly work."4 "Wiki" (pronounced [ˈwiti] or [ˈviti]) is a Hawaiian word meaning "fast" or "quick".56 mso-yfti-tbllook:1184" characteristics Ward Cunningham and co-author Bo Leuf, in their book [http://en.wikipedia.org/wiki/The_Wiki_Way The Wiki Way: Quick Collaboration on the Web], described the essence of the Wiki concept as follows: *A wiki invites all users to edit any page or to create new pages within the wiki Web site, using only a plain-vanilla Web browser without any extra add-ons. *Wiki promotes meaningful topic associations between different pages by making page link creation almost intuitively easy and showing whether an intended target page exists or not. *A wiki is not a carefully crafted site for casual visitors. Instead, it seeks to involve the visitor in an ongoing process of creation and collaboration that constantly changes the Web site landscape. A wiki enables communities to write documents collaboratively, using a simple markup language and a web browser. A single page in a wiki website is referred to as a "wiki page", while the entire collection of pages, which are usually well interconnected by hyperlinks, is "the wiki". A wiki is essentially a database for creating, browsing, and searching through information. A wiki allows non-linear, evolving, complex and networked text, argument and interaction.7 A defining characteristic of wiki technology is the ease with which pages can be created and updated. Generally, there is no review before modifications are accepted. Many wikis are open to alteration by the general public without requiring them to register user accounts. Many edits can be made in real-time and appear almost instantly online. This can facilitate abuse of the system. Private wiki servers require user authentication to edit pages, and sometimes even to read them. Maged N. Kamel Boulos, Cito Maramba and Steve Wheeler write that it is the "openness of wikis that gives rise to the concept of 'Darwikinism', which is a concept that describes the 'socially Darwinian process' that wiki pages are subject to. Basically, because of the openness of wikis and the rapidity with which wiki pages can be edited, the pages undergo a natural selection process like that which nature subjects to living organisms. 'Unfit' sentences and sections are ruthlessly culled, edited and replaced if they are not considered 'fit', which hopefully results in the evolution of a higher quality and more relevant page. Whilst such openness may invite 'vandalism' and the posting of untrue information, this same openness also makes it possible to rapidly correct or restore a 'quality' wiki page."8 Searching Most wikis offer at least a title search, and sometimes a full-text search. The scalability of the search depends on whether the wiki engine uses a database. Some wikis, such as PmWiki, use flat files.10 MediaWiki's first versions used flat files, but it was rewritten by Lee Daniel Crocker in the early 2000s to be a database application. Indexed database access is necessary for high speed searches on large wikis. Alternatively, external search engines such as Google Search can sometimes be used on wikis with limited searching functions in order to obtain more precise results. However, a search engine's indexes can be very out of date (days, weeks or months) for many websites. Implementations Wiki software is a type of collaborative software that runs a wiki system, allowing web pages to be created and edited using a common web browser. It is usually implemented as an application server[[http://en.wikipedia.org/wiki/Wikipedia:Citation_needed citation needed]] that runs on one or more web servers. The content is stored in a file system, and changes to the content are stored in a relational database management system. A commonly implemented software package is MediaWiki, which runs this encyclopedia. See the List of wiki software for further information. Alternatively, personal wikis run as a standalone application on a single computer. WikidPad is an example. Or even single local HTML file with JavaScript inside – like TiddlyWiki. Wikis can also be created on a "wiki farm", where the server side software is implemented by the wiki farm owner. PBwiki, Socialtext, Wetpaint, and Wikia are popular examples of such services. Some wiki farms can also make private, password-protected wikis. Note that free wiki farms generally contain advertising on every page. For more information, see Comparison of wiki farms. Security The open philosophy of most wikis, allowing anyone to edit content, does not ensure that every editor is well-meaning. Virtual vandalism can be a major problem. On larger wiki sites, such as those run by the Wikimedia Foundation, vandalism can go unnoticed for a period of time. Wikis, because of their open access, are susceptible to intentional disruption, known as "trolling". Wikis tend to take a [http://en.wikipedia.org/wiki/Soft_security soft-security]24 approach to the problem of vandalism; making damage easy to undo rather than attempting to prevent damage. Larger wikis often employ sophisticated methods, such as bots that automatically identify and revert vandalism and JavaScript enhancements that show characters that have been added in each edit. In this way vandalism can be limited to just "minor vandalism" or "sneaky vandalism", where the characters added/eliminated are so few that bots do not identify them and users do not pay much attention to them.25 The amount of vandalism a wiki receives depends on how open the wiki is. For instance, some wikis allow unregistered users, identified by their IP addresses, to edit content, whilst others limit this function to just registered users. Most wikis allow anonymous editing without an account,26 but give registered users additional editing functions; on most wikis, becoming a registered user is a short and simple process. Some wikis require an additional waiting period before gaining access to certain tools. For example, on the English Wikipedia, registered users can rename pages only if their account is at least four days old. Other wikis such as the Portuguese Wikipedia use an editing requirement instead of a time requirement, granting extra tools after the user has made a certain number of edits to prove their trustworthiness and usefulness as an editor. Basically, "closed up" wikis are more secure and reliable but grow slowly, whilst more open wikis grow at a steady rate but result in being an easy target for vandalism. A clear example of this would be that of Wikipedia and Citizendium. The first is extremely open, allowing anyone with a computer and Internet access to edit it, making it grow rapidly, whilst the latter requires the users' real name and a biography of themselves, affecting the growth of the wiki but creating an almost "vandalism-free" ambiance. Edit wars can also occur as users repetitively revert a page to the version they favor. Some wiki software allows an administrator to stop such edit wars by locking a page from further editing until a decision has been made on what version of the page would be most appropriate.7 Some wikis are in a better position than others to control behavior due to governance structures existing outside the wiki. For instance, a college teacher can create incentives for students to behave themselves on a class wiki they administer, by limiting editing to logged-in users and pointing out that all contributions can be traced back to the contributors. Bad behavior can then be dealt with in accordance with university policies.10 Potential malware vector Malware can also be problem, as users can add links to sites hosting malicious code. For example, a German Wikipedia article about the Blaster Worm was edited to include a hyperlink to a malicious website. Users of vulnerable Microsoft Windows systems who followed the link would be infected.7 A countermeasure is the use of software that prevents users from saving an edit that contains a link to a site listed on a blacklist of malware sites.27 Communities Many wiki communities are private, particularly within enterprises. They are often used as internal documentation for in-house systems and applications. Some companies use wikis to allow customers to help produce software documentation.28 A study of corporate wiki users found that they could be divided into "synthesizers" and "adders" of content. Synthesizers' frequency of contribution was affected more by their impact on other wiki users, while adders' contribution frequency was affected more by being able to accomplish their immediate work.29 In 2005, the Gartner Group, noting the increasing popularity of wikis, estimated that they would become mainstream collaboration tools in at least 50% of companies by 2009.30 Wikis can be used for project management.313233 Wikis have also been used in the academic community for sharing and dissemination of information across institutional and international boundaries.34 In those settings, they have been found useful for collaboration on grant writing, strategic planning, departmental documentation, and committee work.35 In the mid-2000s, the increasing trend amongst industries toward collaboration was placing a heavier impetus upon educators to make students proficient in collaborative work, inspiring even greater interest in wikis being used in the classroom.7 Wikis have found some use within the legal profession, and within government. Examples include the Central Intelligence Agency's Intellipedia, designed to share and collect intelligence, dKospedia, which was used by the American Civil Liberties Union to assist with review of documents pertaining to internment of detainees in Guantánamo Bay;[[http://en.wikipedia.org/wiki/Wikipedia:Citation_needed citation needed]] and the wiki of the United States Court of Appeals for the Seventh Circuit, used to post court rules and allow practitioners to comment and ask questions. The United States Patent and Trademark Office operates Peer-to-Patent, a wiki to allow the public to collaborate on finding prior art relevant to examination of pending patent applications. Queens, New York has used a wiki to allow citizens to collaborate on the design and planning of a local park. Cornell Law School founded a wiki-based legal dictionary called Wex, whose growth has been hampered by restrictions on who can edit.23 There also exist WikiNodes which are pages on wikis that describe related wikis. They are usually organized as neighbors and delegates. A neighbor wiki is simply a wiki that may discuss similar content or may otherwise be of interest. A delegate wiki is a wiki that agrees to have certain content delegated to that wiki.[[http://en.wikipedia.org/wiki/Wikipedia:Citation_needed citation needed]] One way of finding a wiki on a specific subject is to follow the wiki-node network from wiki to wiki; another is to take a Wiki "bus tour", for example: Wikipedia's Tour Bus Stop. Domain names containing "wiki" are growing in popularity to support specific niches.[[http://en.wikipedia.org/wiki/Wikipedia:Citation_needed citation needed]] The English Wikipedia has the largest user base among wikis on the World Wide Web36 and ranks in the top 10 among all Web sites in terms of traffic.37 Other large wikis include the WikiWikiWeb, Memory Alpha, Wikivoyage and Susning.nu, a Swedish-language knowledge base. Medical and health-related wiki examples include Ganfyd, an online collaborative medical reference that is edited by medical professionals and invited non-medical experts.8 The four basic types of users who participate in wikis are reader, author, wiki administrator and system administrator. The system administrator is responsible for installation and maintenance of the wiki engine and the container web server. The wiki administrator maintains wiki content and is provided additional functions pertaining to pages (e.g. page protection and deletion), and can adjust users' access rights by, for instance, blocking them from editing.38 Growth factors A study of several hundred wikis showed that a relatively high number of administrators for a given content size is likely to reduce growth;39 that access controls restricting editing to registered users tends to reduce growth; that a lack of such access controls tends to fuel new user registration; and that higher administration ratios (i.e. admins/user) have no significant effect on content or population growth.40 Rules Wikis typically have a set of rules governing user behavior. Wikipedia, for instance, has a labyrinthine set of policies and guidelines summed up in its five pillars: Wikipedia is an encyclopedia; Wikipedia has a neutral point of view; Wikipedia is free content; Wikipedians should interact in a respectful and civil manner; and Wikipedia does not have firm rules. Many wikis have adopted a set of commandments. For instance, Conservapedia commands, among other things, that its editors use "B.C." rather than "B.C.E." when referring to years prior to the common era and refrain from "unproductive activity."45 One teacher instituted a commandment for a class wiki, "Wiki unto others as you would have them wiki unto you."10